Rhizoctonia solani is a species of fungus in the order Cantharellales. Basidiocarps are thin, effused, and web-like, but the fungus is more typically encountered in its anamorphic state, as hyphae and sclerotia. The name Rhizoctonia solani is currently applied to a complex of related species that await further research. In its wide sense, Rhizoctonia solani is a facultative plant pathogen with a wide host range and worldwide distribution. It causes various plant diseases such as root rot, damping off, and wire stem. It can also form mycorrhizal associations with orchids.

The Cantharellales are an order of fungi in the class Agaricomycetes. The order includes not only the chanterelles (Cantharellaceae), but also some of the tooth fungi (Hydnaceae), clavarioid fungi, and corticioid fungi (Botryobasidiaceae). Species within the order are variously ectomycorrhizal, saprotrophic, associated with orchids, or facultative plant pathogens. Those of economic importance include edible and commercially collected Cantharellus, Craterellus, and Hydnum species as well as crop pathogens in the genera Ceratobasidium and Thanatephorus/Rhizoctonia.